1. Field of the Invention
This invention relates to a method and a device with which it is possible to carry out registration of a new key, i.e. a key which is not already a registered key such as a master key, in an anti-theft device.
2. Description of Related Art
To enable a vehicle to be used by a number of different people, keys made by copying a master key are sometimes newly added to existing keys for starting the engine of or locking and unlocking doors of the vehicle. In the case of a vehicle having an anti-theft function, when newly adding a key it is necessary to register the new key with an electronic control unit (hereinafter abbreviated to ECU) having an anti-theft function by conducting communication between the ECU and a transponder disposed inside the new key.
In conventional new key registration, authentication data pre-written into a R/O (read-only) transponder disposed inside the new key is read out from the transponder and this data is transmitted to the ECU and written and stored in the ECU.
However, recently, to prevent the copying of keys by thieves, code type transponders, with which once authentication data has been written in the transponder the authentication data cannot be written over or read out, save started to be used.
With a code type transponder, since the authentication data cannot be read out, there is the problem that when the conventional method is used it is not possible to register a new key having a code type transponder in the ECU.